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Vint Cerf on Internet Challenges

timothy posted more than 9 years ago | from the stupid-speed-of-light dept.

The Internet 202

chamilto0516 writes "Phil Windley, a nationally recognized expert in using information technology, drove up to the Univ. of Utah recently hear this years Organick Lecture by Vint Cerf, one of the inventors of the Internet. In his notes, Vint talks about, 'Where is the Science in CS?' He also goes on to talk about real potential trouble spots with the Internet, but there is a bit on Interplanetary Internet (IPN). Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes."

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let's get two out of the way (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#12297673)

I have heard rumors on the internets that Al Gore invented the internet.

well thank goodness we have the internets... (1, Informative)

Anonymous Coward | more than 9 years ago | (#12297761)

so we can disseminate info like this [snopes.com]

Re:let's get two out of the way (5, Informative)

ajs (35943) | more than 9 years ago | (#12297788)

Sigh.... again the Al Gore thing, and again it's modded as funny. It's not. It's a failure of our media to shoot down bad politics.

To quote a site that bothers to keep the quote around for Google's sake:
Gore never claimed that he "invented" the Internet, which implies that he engineered the technology. The invention occurred in the seventies and allowed scientists in the Defense Department to communicate with each other. In a March 1999 interview with Wolf Blitzer, Gore said, "During my service in the United States Congress, I took the initiative in creating the Internet."
And he did take initiative in creating the Internet. In fact, he pushed funding for it through a congress that was convinced that anything attached to the military (and keep in mind that NSF and DARPA *are* connected to the military) was "the enemy". I heard Gore speak back then, and he was passionate about the creation of a national research network and how important it was.

The Internet is here with us today as much because of the funding as because of the science, and Gore was the money man.

Persoanlly, I find some of his politics a bit extreme, but like or hate liberal politics, you have to admit that the media dropped the ball by not calling Bush on this.

Re:let's get two out of the way (0)

Anonymous Coward | more than 9 years ago | (#12297833)

Sigh.... again the Al Gore thing, and again it's modded as funny. It's not. It's a failure of our media to shoot down bad politics.

It was meant as a joke. In every story about the internet, someone invariably posts the Al Gore nonsense and someone else posts the "rumors on the internets" quote from GW. Maybe you missed the "let's get two out of the way" in the subject line.

Re:let's get two out of the way (0)

Anonymous Coward | more than 9 years ago | (#12297837)

I think everyone knows this. It's just funny to say. Well, was funny to say 5 years ago. Now it's jsut old.

"I took the initiative in creating the Internet." (0)

Anonymous Coward | more than 9 years ago | (#12297863)

Oh, riiiight. Gore didn't try to claim he was responsible for the Internet.

What bullshit.

Face it. Gore did try to take credit for "inventing" the Internet, in his usually wooden way.

Gore deserves what he gets, just like W deserves what he gets for saying crap like "misunderestimated".

Re:"I took the initiative in creating the Internet (0)

Anonymous Coward | more than 9 years ago | (#12298160)

So Gore deserves to be essentially forgotten, rejected by his home state.

And Bush deserves 8 years as President, a high probability of solidly tilting the Supreme Court for the rest of MY life, legislation letting his VP's company off the hook for asbestos liability knowingly purchased years before, etc, etc, etc. Maybe I should throw my dictionaries away, too.

Re:let's get two out of the way (4, Informative)

Otter (3800) | more than 9 years ago | (#12298381)

And he did take initiative in creating the Internet. In fact, he pushed funding for it through a congress that was convinced that anything attached to the military (and keep in mind that NSF and DARPA *are* connected to the military) was "the enemy". I heard Gore speak back then, and he was passionate about the creation of a national research network and how important it was.

Absolutely not. Gore entered Congress in 1977, well after any point that could reasonably be construed as the "creation" of the ARPAnet/Internet. It's true that he never claimed to have "invented the Internet" but what he did say is still completely untrue.

fp (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#12297678)

fp

TCP at 40 mins... (1, Funny)

Anonymous Coward | more than 9 years ago | (#12297681)

That is a easy problem to solve... Just set the TCP windows size VERY large.

Interplanetary TCP?? (4, Funny)

jarich (733129) | more than 9 years ago | (#12297683)

Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes.

Well... Duh!

I just assumed everyone ~knew~ we'd be using UDP between planets...

Sheesh... do I have to send a memo about ~everything???

Re:Interplanetary TCP?? (1)

Jonny_eh (765306) | more than 9 years ago | (#12297822)

Wow, so we'll finally have a use for TFTP afterall!

Re:Interplanetary TCP?? (-1, Offtopic)

rainman_bc (735332) | more than 9 years ago | (#12297902)

Wow, so we'll finally have a use for TFTP afterall!


Isn't TFTP used to store the firmware in cable modems? I recal reading a way to hack into your cable modem and have the SNMP data go to your machine, rather than your cable service provider, and TFTP was what you used to get the firmware onto it.

Re:Interplanetary TCP?? (1, Informative)

kernel_dan (850552) | more than 9 years ago | (#12297847)

I just assumed everyone ~knew~ we'd be using UDP between planets...

Why isn't this modded funny? UDP is even worse than TCP: UDP provides no guarantees for message delivery and a UDP sender retains no state on UDP messages once sent onto the network. (For this reason UDP is sometimes expanded to "Unreliable Datagram Protocol".)
Source [wikipedia.org]

Re:Interplanetary TCP?? (1)

jarich (733129) | more than 9 years ago | (#12297856)

Why isn't this modded funny?

Darned if I know why it's not funny... I was trying to be funny when I wrote it! :)

Re:Interplanetary TCP?? (1)

MavEtJu (241979) | more than 9 years ago | (#12298008)

UDP provides no guarantees for message delivery

And neither does TCP. With TCP you have a session and you get all the *received* packets in the same order as they are sent by the source. If one packet, even after retries, can't make it to the other side, your session gets aborted too.

Your TCP layer is as good as your IP layer.
Your UDP layer is as good as your IP layer.

If your IP layer fails, neither TCP nor UDP will do you any good.

Re:Interplanetary TCP?? (1)

kernel_dan (850552) | more than 9 years ago | (#12298203)

IIRC, TCP will send ACK packets to ACKnowlege received data, whereas UDP won't. TCP at least let's you confirm the data is getting through without checking in the application layer.

Re:Interplanetary TCP?? (0)

Anonymous Coward | more than 9 years ago | (#12298659)

TCP first requires a three way handshake. This will be very time consuming. TCP also expects acknowledgement packets to be sent from the receiver based on a timer. If any packets are missing, they will need to be sent again.

Perhaps the best way to do it would be to have two or more UDP streams, time staggered so that if any packets are missing in one stream they will have a reasonably good chance of being found in another stream. Of course this hurts bandwidth. But having a very long lag with TCP handshakes and TCP requests for missing packets is worse.

Re:Interplanetary TCP?? (1)

BlacBaron (875559) | more than 9 years ago | (#12297918)

The 40 minute delay shouldn't be a problem when people can use things like this [slashdot.org] . :)

Especially for telemetry data (3, Informative)

EmbeddedJanitor (597831) | more than 9 years ago | (#12297922)

ftp's policy is to get every byte through byte-perfect and in sequence and it will retry until it gets there. udp just throws out packets and hopes they get there.

Over a 100Mb LAN the difference is effectively nothing, but once you involve slow and lossy networks the difference is considerable. The impact is great enough over terrestrial radio nets and is a zillion times worse interplanetary.

Let's say you have a rover that sends a position message once a second. What you're really interested in, typically, is the most up to date info. If you're using tcp, then you won't get the up to date info until the retries etc have been done to get the old info through (iie. it's noon, but the noon data is not being sent because we're still doing the resneds to get the 8 am data through). This means that the up to date info gets delayed. With udp the lost data is just ignored and the up to date data arrives when it should.

Of course ftp still (might) be a useful way to shift large files etc, but often the udp equivalents (eg. tftp instead of ftp) will be more apropriate.

Re:Especially for telemetry data (2, Funny)

Linker3000 (626634) | more than 9 years ago | (#12298101)

If the data's that important we could always create a multi-part ZIP or RAR file and send it via email - those blighters can sometimes take days to arrive with no apparent ill effect!

Re:Interplanetary TCP?? (1)

Short Circuit (52384) | more than 9 years ago | (#12298318)

Sounds like Squid's going to be getting some upgrades. :)

Seriously, content caches at each end of a high-latency link can solve a lot of the problems without wholescale modification to existing software and hardware infrastructure. Content streaming systems might need post-link buffers, though, to hold the data until the user has been notified that his data was ready.

The high-latency link ought to be an interesting engineering challenge, though, with plenty of oppertunity for advancement of high-throughput data-quality systems like hamming codes and retransmission of data without nonconfirmation. Forget checksums. If your data were to fail one, you'd be screwed, anyway.

Are you... (1)

ImaLamer (260199) | more than 9 years ago | (#12298799)

Al Gore?

What? (1, Interesting)

Anonymous Coward | more than 9 years ago | (#12297698)

Since when did the internet have 'inventors'? In its present form, it has evolved from many different projects and events, and no one person(s) planned for it to be what it is today. It's kind of like the technological equivalent of pizza, it became what it is today thanks to many different people who had different ideas in mind.

Re:What? (0, Offtopic)

Dav3K (618318) | more than 9 years ago | (#12297756)

So is a Hawaiian the byproduct of a bad acid trip, or from someone smoking too much pot?

These are teh questions we want answers to.

Re:What? (1)

emrysk (787256) | more than 9 years ago | (#12297768)

And just as tasty.

What?-Plural. (0)

Anonymous Coward | more than 9 years ago | (#12297829)

"Since when did the internet have 'inventors'? "

The same way TV did.

Re:What? (5, Funny)

topical_surficant (819238) | more than 9 years ago | (#12297889)

Vint Cerf co-authored TCP/IP. You just used it to post.

Vent Cerf = 1
AC = 0

Re:What? (2, Funny)

Usquebaugh (230216) | more than 9 years ago | (#12298068)

Bonus points for telling us where he pinched the idea from?

Re:What? (2, Informative)

diogenesx (580716) | more than 9 years ago | (#12297997)

Vint Cerf is one of two men who designed the TCP/IP protocol that we use today. See http://en.wikipedia.org/wiki/Vint_Cerf/ [wikipedia.org]

Re:What? (5, Interesting)

The boojum (70419) | more than 9 years ago | (#12298034)

Note the key phrase "one of" in the story.

I actually attended this lecture yesterday and Vinton disclaimed the "father of the internet" moniker, saying that he co-designed the original TCP/IP protocol but that he and Bob Kahn and that that work was largely based on the ARPANET design which was in turn based on packet radio, etc. So yes, the man himself said he was just one of a long list contributors.

He did joke though that his son once asked if he was the "brother of the Internet".

He also commented that one of the properties of the system that he was quite happy with was the ease with which others could contribute at any level of the system, including building new application layer protocols on top of the basic protocols without going and needing to go and get permission from someone. People can just go out and write new protocols and build the apps to use them. (e.g. Bit Torrent) He said he thought that the Internet is largely where it is today because of that openness to the contributions of thousands of people.

Awful (3, Insightful)

erick99 (743982) | more than 9 years ago | (#12297702)

What an incredibly poorly written article. There was good content but it was like jogging through a field of boulders......

Awful-Karma. (0)

Anonymous Coward | more than 9 years ago | (#12297754)

" What an incredibly poorly written article. There was good content but it was like jogging through a field of boulders......"

Must be a former Slashdot poster.

Re:Awful (1)

An Onerous Coward (222037) | more than 9 years ago | (#12298167)

I think you're expecting too much. I've tried posting write-ups of talks before, and even if you take notes furiously, it's going to sound like a disorganized mess.

I'm a UofU student, and had planned to go to this lecture. Something came up. So I'm thrilled that someone took the time to do this.

Well, yeah. (3, Informative)

Lally Singh (3427) | more than 9 years ago | (#12297706)

TCP assumes anything over 2 minutes is a lost packet.

One of my favorite kernel comments.... (4, Informative)

Beolach (518512) | more than 9 years ago | (#12297719)

/*
* [...] Note that 120 sec is defined in the protocol as the maximum
* possible RTT. I guess we'll have to use something other than TCP
* to talk to the University of Mars.
* PAWS allows us longer timeouts and large windows, so once implemented
* ftp to mars will work nicely.
*/
(from /usr/src/linux/net/inet/tcp.c, concerning RTT [retransmission timeout])

Re:One of my favorite kernel comments.... (1)

StarDrifter (144026) | more than 9 years ago | (#12297930)

Doesn't RTT mean Round-Trip Time?

http://en.wikipedia.org/wiki/RTT [wikipedia.org]

Re:One of my favorite kernel comments.... (1)

Beolach (518512) | more than 9 years ago | (#12298125)

Heh, I just copied & pasted the fortune cookie. I would have said Round Trip Time, too.

Vint Cerf? (3, Funny)

Anonymous Coward | more than 9 years ago | (#12297724)

It's a person? I thought it was a number at first.

IPI Important spots. (-1, Offtopic)

TiggertheMad (556308) | more than 9 years ago | (#12297739)

I look forward to the Interplanetary Internet, as it will allow humans to extend their communication capabilities out into the solar system, as a first step out into the great unknown.

But mostly, I'm just waiting for the SPACE PR0N! w00t w00t!

Come on here... (3, Funny)

La Camiseta (59684) | more than 9 years ago | (#12297752)

Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes.

That's what subspace communication is for. I would hope that a geek of his caliber has at least watched some Star Trek.

Re:Come on here... (0)

Anonymous Coward | more than 9 years ago | (#12297865)

Well, once we find the Stargate, radio transmission through the wormhole will work just fine.. This won't even be an issue!

No Thanks (-1, Troll)

rudy_wayne (414635) | more than 9 years ago | (#12297760)

Vint Cerf may have "invented the Internet" but his association with ICANN, one of the major scumbag organizations of the Internet, destroys all of his credibility.

Re:No Thanks (1)

Yaa 101 (664725) | more than 9 years ago | (#12297928)

The UN isn't doing that much better, and the ITU is only for their own power.

BTW, Vint Cerf didn't invent the internet, he co-invented TCP/IP.

The Internet is a much older vision.
You can read some of it here: http://www.computerhistory.org/exhibits/internet_h istory/

Re:No Thanks (1)

Yaa 101 (664725) | more than 9 years ago | (#12297944)

slashdot software fuckedup the url again, remove the space in there...

Re:No Thanks (0)

Anonymous Coward | more than 9 years ago | (#12298320)

slashdot software fuckedup the url again

I tihnk the problem lies with the poster (this means you) not knowing how to make a proper link. [computerhistory.org]

Re:No Thanks or Why I love the Internets (1)

WillAffleckUW (858324) | more than 9 years ago | (#12297994)

The Internet is a much older vision.
You can read some of it here: http://www.computerhistory.org/exhibits/internet_h istory/


I know, I was on the first ARPANET. Back when I was at SFU, and 1200 baud was something you couldn't even get at the UBC labs.

So, yes, technically, Vint Cerf didn't invent the Internet per se, but then TCP/IP is what most people think of as the internet. And Al Gore was the primary lead on getting funding, so he did invent the Internet, since that was ARPANET, the real internet.

And, yes, I was in the military back then. But it's none of your business.

P2P (0)

Anonymous Coward | more than 9 years ago | (#12297782)

How long until P2P is Planet-to-Planet?

everyone please (-1, Troll)

thundercatslair (809424) | more than 9 years ago | (#12297798)

First of all, this isn't a troll, offtopic, overrated, post. I have been karma whoring ass off trying to get excellent karma so I can get mod points, in like the month I have had it I was given 5 points, this is bullshit. So long slashdot.

Re:everyone please (0, Troll)

thundercatslair (809424) | more than 9 years ago | (#12297970)

fuck I said this post wasn't a troll, I should get like +infinity insightful.

Google (1)

Locarius (798304) | more than 9 years ago | (#12297831)

Somehow I don't think he will be able to convince the Google boys that there is no science going on on the Internet.

Latency over lightyears... (-1)

strredwolf (532) | more than 9 years ago | (#12297860)

Since latency's going to be over lightyears away, and TCP's no good using standard broadcast methods... ...we'll have to use something different for IPN communications. Right now we have copper, fiber, and radio. We need something that'll be as fast as fiber, but will stretch way way longer in distance.

Current radio's a broadcast. Can't do that, especially with package leakage.

I belive there was some experiments in quantum transmissio of data, in which an electron was split and one half sent to Munich, the other sent to Venice, and transmissions where near-instantaneous.

Re:Latency over lightyears... (0)

Anonymous Coward | more than 9 years ago | (#12297929)

Since latency's going to be over lightyears away

Umm... huh? Latency is a time period. Lightyears are distance units. It's like saying "my car is a metre faster than yours".

Re:Latency over lightyears... (1)

Anonymous Cowpat (788193) | more than 9 years ago | (#12297965)

It's like saying "my car is a metre faster than yours".

Yeah? well mine can do the Kessel run in 12 parsecs!

Re:Latency over lightyears... (2, Funny)

14erCleaner (745600) | more than 9 years ago | (#12297976)

That sounds like a hardware problem to me. Therefore, most computer scientists will ignore it.

Re:Latency over lightyears... (0)

Anonymous Coward | more than 9 years ago | (#12298042)

Therefore, most computer scientists will ignore it.

Until it comes time to write drivers, then they'll all be whining about inconsequential things like "dammit, how the hell am I supposed to assert this pin AND move 3KB of data into the device, all within a single host clock cycle? Did the engineer smoke his timing diagrams?"

Re:Latency over lightyears... (1)

Anonymous Luddite (808273) | more than 9 years ago | (#12298231)

>> That sounds like a hardware problem to me.

heheh. that sounds like an application developer to me...

Re:Latency over lightyears... (1)

RealAlaskan (576404) | more than 9 years ago | (#12298267)

That sounds like a hardware problem to me. Therefore, most computer scientists will ignore it.

Since most computer scientists are mathematicians at heart, they'll solve the problem by saying: ``Assume a network of super-luminal [wolfram.com] communications devices.''

Re:Latency over lightyears... (5, Informative)

menscher (597856) | more than 9 years ago | (#12298083)

Since latency's going to be over lightyears away

Latency is measured in units of time. Lightyears are a measure of distance.

TCP's no good using standard broadcast methods

Huh? If I knew what you meant to say, it'd be easier to show you were wrong...

We need something that'll be as fast as fiber, but will stretch way way longer in distance.

So, like, line-of-sight laser communication?

Current radio's a broadcast. Can't do that, especially with package leakage.

How do you think we're communicating with the Mars rovers now? Or other planetary explorers?

I belive there was some experiments in quantum transmissio of data, in which an electron was split and one half sent to Munich, the other sent to Venice, and transmissions where near-instantaneous.

You can instantaneously determine what the other side received, but no information can be transmitted this way.

I see you have a low user-id, and therefore have learned to get modded up for saying stuff that is nonsensical and wrong. I must admit I'm impressed. I earn all my mod points the hard way.

OT: Mencher's defence (1)

pegr (46683) | more than 9 years ago | (#12298276)

Since latency's going to be over lightyears away

Latency is measured in units of time. Lightyears are a measure of distance.


He could be referring to the latency incurred with a transmission distance of a light year... What is the latency of a lightyear? Assuming light speed communication, one year. Of course, add a bit for frame/packet decode...

Yeah, the rest of the post is meaningless... Kinda like all of this one!

Re:Latency over lightyears... (1)

DA-MAN (17442) | more than 9 years ago | (#12298095)

Since latency's going to be over lightyears away, and TCP's no good using standard broadcast methods...

Lightyear is not a metric for time time, it's a metric for distance. Light travels @ 186,000 miles per second, a light year is equivalent to 186,000 * (60sec*60min*24hrs*365.25days) or approximately 5,869,713,600,000 miles.

Right now we have copper, fiber, and radio. We need something that'll be as fast as fiber, but will stretch way way longer in distance.

As far as I know fiber (optics) use light to travel within the cable. This means that the fiber cable is limited to the speed of light. Radio broadcasts, much like visible light, are forms of energy (electromagnetic) that travel at the speed of (get ready for this) light.

If you had a fiber cable from here to Mars, the latency would be the same as radio. It would most certainly have better throughput, but that's another story.

Re:Latency over lightyears... (1)

DeuceTre (785433) | more than 9 years ago | (#12298577)

actually no - the speed of light changes depending on the medium it is passed through. data travelling through space would approach the speed of light through a vacumm, the number you're using in your equation for a light year. however, the speed of light in fiber is about 30% slower due to the relatively higher refractive index in the cable and thus would be much slower than radio transmissions.

more info can be found at: http://en.wikipedia.org/wiki/Speed_of_light#Intera ction_with_transparent_materials

Re:Latency over lightyears... (1)

shift.red.avni (858445) | more than 9 years ago | (#12298220)

I'm not surprised when I see completely non-sensical posts get modded up on Slashdot anymore, but this has to be the most blatant example I've ever seen.

That this post got to +5 Interesting is proof that Slashdot's community moderation concept is a failure.

Re:Latency over lightyears... (0)

Anonymous Coward | more than 9 years ago | (#12298432)

I know. It makes me stop reading slashdot every couple days, because I get so fed up with the misinformation.

In the 70s, NASA had little tiny satellites sending back images (hint to the others: that data was reliably transmitted too!) of planets from places much much farther away than Mars.

People don't realize, but even there are problems using TCP to talk to satellites in orbit around Earth. What happens is as the satellites move, your RTT slowly grows (as it gets further away), and it gets to a point where it comes time to switch to a new satellite. So your RTT will instantly jump.

TCP was not designed with this mind (Actually, TCP was not designed with many, many current situations in mind, and has had many hacks tacked onto it). But people are trying to work out ways to minimize the effect.

Re:Latency over lightyears... (4, Informative)

5E-0W2 (767094) | more than 9 years ago | (#12298235)

You can't transfer information over entangled particles. Furthermore, faster than light information transfer violates relativity.

Classic Short Story (0)

kraksmokr (216277) | more than 9 years ago | (#12297885)

There was a classic sci-fi short story from the 1940s or 1950s on this topic. The problem was "solved" by someone's mother who just happened to be in the "control room", baking cookies or some such. She basically proposed a full duplex scheme where two parties just stream data to each other, sending and listening at the same time, and you send a retransmit request if you miss something.

Re:Classic Short Story (1)

SunPin (596554) | more than 9 years ago | (#12297942)

Great troll. I'll have to use that on somebody sometime.

"My Son, The Physicist" (1)

kraksmokr (216277) | more than 9 years ago | (#12298030)

I found it! It's a 1962 story by Asimov!

Vint Cerf: Value of the net vs. cost of the net (5, Informative)

G4from128k (686170) | more than 9 years ago | (#12297890)

I heard Vint Cerf speak at an e-business conference (remember when those were popular?).

He talked extensively about how the layered architecture of the internet poses a serious challenge to business models. The fact that any application can communicate through any physical medium (of sufficient bandwidth) was great for interoperability, but hard on businesses that provide the physical layer.

The problem is that all of the value is in the application layer -- people want to run software, download movies, chat with friends, etc. Whether the data flows on copper, fiber, or RF is irrelevant to the end-user and the layered architecture ensures that this is irrelevant. In contrast, a lot of the cost is in that "irrelevant" physical layer -- the last mile is still very expensive (we can hope WiMax reduces this problem). This gulf between cost and value forces physical infrastructure providers into a position of being a commodity providers with severe cost competition. If the end-user doesn't care how their data is carried, then they tend to treat bandwidth as a commodity.

I think he was wearing his MCI hat at the time of this talk and was influenced by the beginnings of the dot-com crash. MCI's subsequent bankruptcy was not surprising. Understanding this issue explains why telecom companies don't want municipal wifi and insist that you only network your cellphone through their networks. The only way to make infrastructure pay is to bind the high-value software application layer to the high-cost hardware layer. But this strategy violates the entire layered model and enrages consumers.

Expert ??? Who is Phil Whendley ? (2)

MerlynEmrys67 (583469) | more than 9 years ago | (#12297900)

So, this guys claim to fame is he worked at Excite@Home and was the CIO of the state of Utah...
Well, and maybe having his own website up there at phil.whendley.com.

Seems kind of far from a Nationally recognized expert to me. I'd never heard of him - why do I associate his name with a talk that Vint Cerf gave and apparently this guy gave no value too, other than driving there and listening

Software Quality (4, Interesting)

nokiator (781573) | more than 9 years ago | (#12297901)

It is rather amazing that there appears to be a consensus among industry experts that there has not been any improvement in code quality over the past 30 years or so despite the development of a vast number of new tools and languages. It is true that the size and scope of the average application has grown by leaps and bounds. But most likely, the primary contributing factor to these kind of quality problems is the prevalent time-to-market pressuer in the software industry which is typically coupled with severe underestimation of time and resources required for projects.

Even if CS came up with a scientific solution to improve code quality, it would be an interesting exercise to see if the industry will be willing to absorb the costs associated with such a solution. Especially in an environment where end customers are well-trained to accept and deal with software quality issues.

Re:Software Quality (1)

Peter La Casse (3992) | more than 9 years ago | (#12298394)

Even if CS came up with a scientific solution to improve code quality, it would be an interesting exercise to see if the industry will be willing to absorb the costs associated with such a solution.

I think they would, if it were cost effective. Industry spends tons of money and wastes tons of time on "process" that I'm sure they'd rather spend on other stuff.

Gateways (1)

lappy512 (853357) | more than 9 years ago | (#12297911)

Then that is why we have a gateway, and we use that to bridge two internets. Or, invent some communication that is instant. :D

Someone correct me if this is wrong (3, Insightful)

kid_wonder (21480) | more than 9 years ago | (#12297921)

40 minutes = 2400 seconds
Speed of light = 299,792.458 kilometers per second
Distance from Earth to Mars: 55,700,000 kilometers (minimum) 401,300,000 km (maximum)

Time of travel at speed of light to mars: 401,300,000/299,792.458 = ~1339 second

Since Mars is supposedly the first place we're likely to go farther away than the moon it seems that we are fine for now.

Right? Or is there not a way to send data in form of light, or do radio waves travel slower than light?

Anyway, someone correct me here

Re: Radio waves = speed of light (1)

kid_wonder (21480) | more than 9 years ago | (#12297937)

"Radio waves are a kind of electromagnetic radiation, and thus they move at the speed of light."

Just found that on a web site so it must be true

Round trip (0)

Anonymous Coward | more than 9 years ago | (#12297964)

Double the distance.

And the 40 minutes was pulled out of a rectal database - it doesn't mean anything. TCP/IP timeouts are usually on the order of a minute or two, IIRC. (been a long time since I've been down in that code...)

Re:Someone correct me if this is wrong (0)

Anonymous Coward | more than 9 years ago | (#12298006)

the distance from earth to mars is continuously varying. at some points, radio communications would probably have to be bounced off of a third point satellite so as to avoid the sun. however, even when mars and the earth are on opposite sides of the sun, some radio contact may be possible, if we factor in the curvature of space-time due to the sun's gravity, and send a signal that is distinct from the solar interference.

Re:Someone correct me if this is wrong (5, Informative)

rewt66 (738525) | more than 9 years ago | (#12298023)

I believe that TCP requires an acknowledgement that the other end of the link received the packet. So, using your numbers, that would be 1339 * 2 = 2678 seconds, which is 44.63 minutes (40 minutes in round figures).

Re:Someone correct me if this is wrong (1)

AdamHaun (43173) | more than 9 years ago | (#12298162)

All electromagnetic radiation travels at the same speed. Different signals are placed into groups like radio and visible light based on their frequency spectra(that is, how the signal varies with time). It's just a convenience; physically they're still more or less the same thing.

Re:Someone correct me if this is wrong (1)

autocracy (192714) | more than 9 years ago | (#12298287)

You're probably spot-on. I don't really care to verify figures, but yes, radio waves travel the same speed; wavelength and other minute details aside (does that have an effect? whatever.. short response). Latency is Rount Trip Time, though... so value * 2 (after all, ping is time between sending packet and getting packet reply BACK). Roughly 40 minutes.

Doesn't IPv6 fix this? (2, Interesting)

WillAffleckUW (858324) | more than 9 years ago | (#12297957)

I thought, years ago when I was looking at it, that IPv6 had a TTL that was modifiable, and thus wouldn't time out.

But, as a practical matter, it would work better as an FTP request does, where you stream the data in blocks and resend any missed blocks later. This would work fairly well for lossy protocols like JPEG or suchlike, but a good image format should be able to handle it, but time stop/start protocols might get glitched and would have to be replaced.

Anyone for MP7? TUFF instead of TIFF?

The other question is, would this be on the same network, or would, given the very small number of network nodes concerned, it be on a network that we bridge to and translate as needed, buffering the data streams on each end.

Now, if you had a martian sandstorm for a few days, that's probably not going to be that helpful, but you get the idea ....

Need wormholes (1)

QuantumG (50515) | more than 9 years ago | (#12297960)

Of course, that's got me thinking about Pandora's Star again and now I'm depressed as it has been 12 freakin' months and Peter F. Hamilton still hasn't completed Judas Unleashed.

But seriously, imagine if CERN discovered a workable way to make microscopic wormholes. All you'd need is one big enough to send a stream of photons through. Hook up your optic fibre and you've got yourself a zero latentcy round-the-world communications network. It'd certainly change gaming.

tcp/ip doesnt work well when its deluged with spam (1)

Indy1 (99447) | more than 9 years ago | (#12297969)

shame he works for the #1 spam support company [spamhaus.org] in the world.

his company adds new spammers on an almost daily basis, just check the dates on the various sbl records.

Nationally Recognized Expert (2, Funny)

tyler_larson (558763) | more than 9 years ago | (#12298003)

Phil Windley, a nationally recognized expert in using information technology...

Wow. If I had known that he was such a celebrity, I probably would have paid more attention in his Enterprise Systems class at BYU.

I guess it's nice to learn from someone important who doesn't act like the world revolves around him.

Latency (2, Funny)

nsuccorso (41169) | more than 9 years ago | (#12298040)

Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes.

...as any DirecWay customer can readily attest to...

Re:Latency (0)

Anonymous Coward | more than 9 years ago | (#12298761)

And don't forget Starband. 650ms ping time, minimum. Cache and forward times stretched it to 2 minutes a lot of the time. 10 minutes wasn't surprising or all that unusual.

Are they (*band) still around or did the rabid Palestinians and Lebonese overrun their earth station and sap their pristine humanoid fluids?

Where is the "science" in CS (4, Insightful)

jgold03 (811521) | more than 9 years ago | (#12298119)

I think people generally don't understand what computer science is. CS isn't a 4 year degree to learn how to program or set up a network. It's about having the theoretical background to be able to analyze and evaluate comptuter technologies. Classes like automata theory and theoretical data structure classes are necessary to be able to both 1) apply a real solution to a problem and 2) be able to argue the validity of that solution. There is a lot of science in CS.

Very VERY short recap (1)

Che Guevarra (85906) | more than 9 years ago | (#12298136)

Vint hates the chaos of evolving systems and identifies all the protocols in flux. Most solutions not offered. Vince will be able to call home from Mars. I skimmed it, sorry.

Vint hates the chaos of evolving systems ... (0)

Anonymous Coward | more than 9 years ago | (#12298416)

So Vint hates the most important property of the Internet, emergence.

Interesting ...

Simple Case of Temporal Mechanics (1)

Quirk (36086) | more than 9 years ago | (#12298179)

I'm with Captain Janeway in her dislike of temporal mechanics, but this seems like a problem the crew in TOS solved by slinging the Enterprise one way or another around the Sun. Sling the data packets x number of times around the Sun and fling them the appropriate distance into the future, or, possibly, on occasion, into the past. But then again I could be wrong; as noted above I hate temporal mechanics.

tro88lkore (-1, Troll)

Anonymous Coward | more than 9 years ago | (#12298315)

pVroject. Today, as for membership.

Interplanetary TCP HOWTO (3, Interesting)

Effugas (2378) | more than 9 years ago | (#12298324)

Realtime communication with a Martian node is physically impossible. It's simply too far away.

Realistically, we might see a proxy architecture as follows:

1) All traffic is "queued" at an earth-bound substation. Communication is TCP-reliable to this node; transport layer acknowledgements are degraded to "message received by retransmitter" (end-to-gateway) rather than "message received by Mars"(end-to-end). Since both Earth and Mars are in constant rotation, a "change gateway" message would need to exist to route interplanetary traffic to a different satellite node (think "global handoff").

2) Transmission rates from Earth to Mars are constant, no matter the amount of data to send. Extra link capacity is consumed by large-block forward error correction mechanisms. Conceivably, observed or predicted BER's could drive minimum FEC levels (i.e. the more traffic being dropped, due to the relative positions of the Earth and Mars, the less traffic you'd be willing to send in lieu of additional error correction data.

3) Applications would need to be rewritten towards a queue mentality, i.e. the interplanetary link is conceivably the ultimate "long fat pipe". Aggressively publishing content across the interplanetary gap would become much more popular. As much content has gone dynamic, one imagines it becoming possible to publish small virtual machines that emulate basic server side behavior within the various proxies.

You'd think all this was useless research, as there's no reason to go to Mars -- but TCP doesn't just fail when asked to go to Mars; it's actually remarkably poor at handling the multi-second lag inherent in Geosat bounces. Alot of the stuff above is just an extension of what we've been forced to do to deal with such contingencies.

--Dan

First *Stargate* Post!! (1)

dubbayu_d_40 (622643) | more than 9 years ago | (#12298415)

Gosh, I can't believe there hasn't been a stargate joke yet. Amazing.

Sync: The Emerging Science of Spontaneous Order (0)

Anonymous Coward | more than 9 years ago | (#12298467)

"Strogatz is a Cornell mathematician and pioneer of the science of synchrony, which brings mathematics, physics and biology to bear on the mystery of how spontaneous order occurs at every level of the cosmos, from the nucleus on up. In this eminently accessible and entertaining book, Strogatz explores the mysterious synchrony achieved by fireflies that flash in unison by the thousands, and the question of what makes our own body clocks synchronize with night and day and even with one another."

Sync [amazon.com]

ping (0)

Anonymous Coward | more than 9 years ago | (#12298473)

$ ping beagle2.mars.sol # --- .sol TLD for our solar system
PING beagle2.mars.sol (10.42.0.2) 56(84) bytes of data.
64 bytes from 10.42.0.2: icmp_seq=1 ttl=64 time=2485995.132 ms # --- about 40 min
64 bytes from 10.42.0.2: icmp_seq=2 ttl=64 time=2485995.197 ms
64 bytes from 10.42.0.2: icmp_seq=3 ttl=64 time=2485995.163 ms
Destination Host Unreachable # --- beagle2 crash
Destination Host Unreachable
Destination Host Unreachable

Sorry for this obligatory UNIX joke, but I couldn't resist !

The only science is debugging code (3, Interesting)

rufusdufus (450462) | more than 9 years ago | (#12298550)

For me, its not science if it doesn't involve the methods of empiricism. Observation, hypothesis, repeat.

The only time this really happens with computers is troubleshooting.
Programmers may think in a logical or analytical way, but thats not science. And its a good thing to. If programmers weren't allowed to make stuff up as they went along but instead had to use scientific method for everything they did not many progams would be completed.

Interplanetary Communications (0)

Curunir_wolf (588405) | more than 9 years ago | (#12298603)

Apparently, the flow control mechanism of TCP doesn't work well when the latency goes to 40 minutes."

Ok, I admit I didn't RTFA, but this is just stupid. Why would anybody even thing about sending an interplanetary spacecraft out expecting to communicate with it using a determanistic protocol. Is this a joke, or what? The engineering that goes into designing anything that will be sent off-planet is incredible. Even satellites are designed with systems that not only deal with the few-second latency, but also account for the relativistic influences on time differences due to gravity.

Ok, maybe this is a joke, but it's poor attempt at one if it is. I mean, 40 minutes! It's only, what, 9 minutes at light-speed to the sun. Who TF is he talking about communicating with?!?!?

WTF? (0)

Anonymous Coward | more than 9 years ago | (#12298699)

That was the most incomprehensible blurb I have read on Slashdot.

UUCP (1)

John Hasler (414242) | more than 9 years ago | (#12298770)

> Apparently, the flow control mechanism of TCP
> doesn't work well when the latency goes to 40
> minutes.

UUCP, however, works just fine.
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